POLLINATION AND PROGAMIC PHASE IN NOPAL Opuntia ficus-indica (L) Miller) TUNERO

Abstract

The pollination mechanisms and the proghamic phase were studied in two forms of prickly pear (Opuntia ficus-indica (L) Miller). The flowers showed characteristics of ephemeral flowers, opening and closing in the same day. The observations of pollen grain deposition revealed that the stigmas are covered by a mixture of pollen grains derived from cross and self-pollination. In one of the evaluated forms, anther dehiscence was observed before flower opening (preanthesis cleistogamy). Pollen grain germination and pollen tube growth occur relatively fast, since pollen tubes were observed at the base of the style 24 hr after flower opening. The style is hollow, and the pollen tubes develop on the surface of the glan dular epidermis of the stylar canal. A high number of pollen tubes started to  grow in the upper half of the style as compared to the number of pollen tubes growing at the base of the style. Ovule fertil ization occurs progressively, starting two days after flowering opening and ending eight days later.